An integrated dielectrophoresis-active hydrophoretic microchip for continuous particle filtration and separation

Microfluidic manipulation of biological objects from mixture has a significant application in sample preparation and clinical diagnosis. This work presents a dielectrophoresis-active hydrophoretic device for continuous label-free particle separation and filtration. This device comprises interdigitated electrodes and a hydrophoretic channel. According to the difference of lateral positions of polystyrene particles, the device can run at separation or filtration modes by altering the power supply voltages. With an applied voltage of 24 V_p-p, both 3 and 10 μm beads had close lateral positions and were redirected to the same outlet. Under a voltage of 36 V_p-p, beads with the diameters of 3 and 10 μm had different lateral positions and were collected from the different outlets. Separation of 5 and 10 μm particles was achieved to demonstrate the relatively small size difference of the beads. This device has great potential in a range of lab-on-a-chip applications.